/*
   Bacula(R) - The Network Backup Solution

   Copyright (C) 2000-2025 Kern Sibbald

   The original author of Bacula is Kern Sibbald, with contributions
   from many others, a complete list can be found in the file AUTHORS.

   You may use this file and others of this release according to the
   license defined in the LICENSE file, which includes the Affero General
   Public License, v3.0 ("AGPLv3") and some additional permissions and
   terms pursuant to its AGPLv3 Section 7.

   This notice must be preserved when any source code is
   conveyed and/or propagated.

   Bacula(R) is a registered trademark of Kern Sibbald.
*/
/*
   Derived from smtp-orig.c

   AUTHOR(S)
     W.Z. Venema
     Eindhoven University of Technology
     Department of Mathematics and Computer Science
     Den Dolech 2, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
   CREATION DATE
     Wed Dec 1 14:51:13 MET 1993
   LAST UPDATE
     Fri Aug 11 12:29:23 MET DST 1995
   COPYRIGHT

   Copyright 1993-1995 by Wietse Venema. All rights reserved. Some
   individual files may be covered by other copyrights.

   This material was originally written and compiled by Wietse Venema at
   Eindhoven University of Technology, The Netherlands, in 1993, 1994, and
   1995. Redistribution and use in source and binary forms, with or without
   modification, are permitted provided that this entire copyright notice is
   duplicated in all such copies.

   This software is provided "as is" and without any expressed or implied
   warranties, including, without limitation, the implied warranties of
   merchantibility and fitness for any particular purpose.
*/

#include "bacula.h"
#include "jcr.h"
#define MY_NAME "bsmtp"

#if defined(HAVE_WIN32)
#include <lmcons.h>
#endif

#ifndef MAXSTRING
#define MAXSTRING 254
#endif

enum resolv_type {
   RESOLV_PROTO_ANY,
   RESOLV_PROTO_IPV4,
   RESOLV_PROTO_IPV6
};

static FILE *sfp;
static FILE *rfp;

static char *from_addr = NULL;
static char *cc_addr = NULL;
static char *subject = NULL;
static char *err_addr = NULL;
static const char *mailhost = NULL;
static char *reply_addr = NULL;
static char *sender_addr = NULL;
static char *custom_headers[10];
static int mailport = 25;
static char my_hostname[MAXSTRING];
static bool content_utf8 = false;
static resolv_type default_resolv_type = RESOLV_PROTO_IPV4;

/*
 * Take input that may have names and other stuff and strip
 *  it down to the mail box address ... i.e. what is enclosed
 *  in < >.  Otherwise add < >.
 */
static char *cleanup_addr(char *addr, char *buf, int buf_len)
{
   char *p, *q;

   if ((p = strchr(addr, '<')) == NULL) {
      snprintf(buf, buf_len, "<%s>", addr);
   } else {
      /* Copy <addr> */
      for (q=buf; *p && *p!='>'; ) {
         *q++ = *p++;
      }
      if (*p) {
         *q++ = *p;
      }
      *q = 0;
   }
   Dmsg2(100, "cleanup in=%s out=%s\n", addr, buf);
   return buf;
}

/*
 * get_response - examine message from server
 */
static void get_response(void)
{
   char buf[1000];

   Dmsg0(50, "Calling fgets on read socket rfp.\n");
   buf[3] = 0;
   while (fgets(buf, sizeof(buf), rfp)) {
      int len = strlen(buf);
      if (len > 0) {
         buf[len-1] = 0;
      }
      if (debug_level >= 10) {
         fprintf(stderr, "%s <-- %s\n", mailhost, buf);
      }
      Dmsg2(10, "%s --> %s\n", mailhost, buf);
      if (!isdigit((int)buf[0]) || buf[0] > '3') {
         Pmsg2(0, _("Fatal malformed reply from %s: %s\n"), mailhost, buf);
         exit(1);
      }
      if (buf[3] != '-') {
         break;
      }
   }
   if (ferror(rfp)) {
      fprintf(stderr, _("Fatal fgets error: ERR=%s\n"), strerror(errno));
   }
   return;
}

/*
 * chat - say something to server and check the response
 */
static void chat(const char *fmt, ...)
{
   va_list ap;

   va_start(ap, fmt);
   vfprintf(sfp, fmt, ap);
   va_end(ap);
   if (debug_level >= 10) {
      fprintf(stdout, "%s --> ", my_hostname);
      va_start(ap, fmt);
      vfprintf(stdout, fmt, ap);
      va_end(ap);
   }

   /* Send message to server and parse its response. */
   fflush(sfp);
   if (debug_level >= 10) {
      fflush(stdout);
   }
   get_response();
}

/*
 * usage - explain and bail out
 */
static void usage()
{
   fprintf(stderr,
_("\n"
"Usage: %s [-f from] [-h mailhost] [-s subject] [-c copy] [recipient ...]\n"
"       -4          forces bsmtp to use IPv4 addresses only.\n"
#ifdef HAVE_IPV6
"       -6          forces bsmtp to use IPv6 addresses only.\n"
#endif
"       -8          set charset to UTF-8\n"
"       -a          use any ip protocol for address resolution\n"
"       -c          set the Cc: field\n"
"       -d <nn>     set debug level to <nn>\n"
"       -dt         print a timestamp in debug output\n"
"       -f          set the From: field\n"
"       -h          use mailhost:port as the SMTP server\n"
"       -s          set the Subject: field\n"
"       -r          set the Reply-To: field\n"
"       -S          set the Sender: field\n"
"       -H          add a custom line to the mail header\n"
"       -l          set the maximum number of lines to send (default: unlimited)\n"
"       -?          print this message.\n"
"\n"), MY_NAME);

   exit(1);
}

/*
 * Return the offset west from localtime to UTC in minutes
 * Same as timezone.tz_minuteswest
 *   Unix tz_offset coded by:  Attila Fülöp
 */
static long tz_offset(time_t lnow, struct tm &tm)
{
#if defined(HAVE_WIN32)
#if defined(HAVE_MINGW)
__MINGW_IMPORT long     _dstbias;
#endif
#if defined(MINGW64)
# define _tzset tzset
#endif
   /* Win32 code */
   long offset;
   _tzset();
   offset = _timezone;
   if (tm.tm_isdst) {
      offset += _dstbias;
   }
   return offset /= 60;
#else

   /* Unix/Linux code */
   struct tm tm_utc;
   time_t now = lnow;

   (void)gmtime_r(&now, &tm_utc);
   tm_utc.tm_isdst = tm.tm_isdst;
   return (long)difftime(mktime(&tm_utc), now) / 60;
#endif
}

static void get_date_string(char *buf, int buf_len)
{
   time_t now = time(NULL);
   struct tm tm;
   char tzbuf[MAXSTRING];
   long my_timezone;

   /* Add RFC822 date */
   (void)localtime_r(&now, &tm);

   my_timezone = tz_offset(now, tm);
   strftime(buf, buf_len, "%a, %d %b %Y %H:%M:%S", &tm);
   snprintf(tzbuf, sizeof(tzbuf), " %+2.2ld%2.2u", -my_timezone / 60, (unsigned int)abs(my_timezone) % 60);
   strcat(buf, tzbuf);              /* add +0100 */
   strftime(tzbuf, sizeof(tzbuf), " (%Z)", &tm);
   strcat(buf, tzbuf);              /* add (CEST) */
}

/*********************************************************************
 *
 *  Program to send email
 */
int main (int argc, char *argv[])
{
   char buf[1000];
   int i, ch;
   unsigned long maxlines, lines;
#if defined(HAVE_WIN32)
   SOCKET s;
#else
   int r;
   int s = -1;
   struct passwd *pwd;
#endif
   char *cp, *p;
#ifdef HAVE_GETADDRINFO
   int res;
   struct addrinfo hints;
   struct addrinfo *ai, *rp;
   char mail_port[10];
#else
   struct hostent *hp;
   struct sockaddr_in sin;
#endif
#ifdef HAVE_IPV6
   const char *options = "468ac:d:f:h:r:s:l:S:H:?";
#else
   const char *options = "48ac:d:f:h:r:s:l:S:H:?";
#endif

   int custom_header_count = 0;
   int custom_header_max = (sizeof(custom_headers) / sizeof(char *));

   setlocale(LC_ALL, "en_US");
   bindtextdomain("bacula", LOCALEDIR);
   textdomain("bacula");

   my_name_is(argc, argv, "bsmtp");
   maxlines = 0;

   while ((ch = getopt(argc, argv, options)) != -1) {
      switch (ch) {
      case '4':
         default_resolv_type = RESOLV_PROTO_IPV4;
         break;

#ifdef HAVE_IPV6
      case '6':
         default_resolv_type = RESOLV_PROTO_IPV6;
         break;
#endif

      case '8':
         content_utf8 = true;
         break;

      case 'a':
         default_resolv_type = RESOLV_PROTO_ANY;
         break;

      case 'c':
         Dmsg1(20, "cc=%s\n", optarg);
         cc_addr = optarg;
         break;

      case 'd':                    /* set debug level */
         if (*optarg == 't') {
            dbg_timestamp = true;
         } else {
            debug_level = atoi(optarg);
            if (debug_level <= 0) {
               debug_level = 1;
            }
         }
         Dmsg1(20, "Debug level = %d\n", debug_level);
         break;

      case 'f':                    /* from */
         from_addr = optarg;
         break;

      case 'h':                    /* smtp host */
         Dmsg1(20, "host=%s\n", optarg);
         p = strchr(optarg, ':');
         if (p) {
            *p++ = 0;
            mailport = atoi(p);
         }
         mailhost = optarg;
         break;

      case 's':                    /* subject */
         Dmsg1(20, "subject=%s\n", optarg);
         subject = optarg;
         break;

      case 'r':                    /* reply address */
         reply_addr = optarg;
         break;

      case 'S':                    /* sender address */
         sender_addr = optarg;
         break;

      case 'H':                    /* custom header "XXXX: YYYYYYY" */
         if (custom_header_count<custom_header_max) {
            custom_headers[custom_header_count++] = optarg;
         } else {
            fprintf(stderr, "Too many custom header, ignored\n");
         }
         break;

      case 'l':
         Dmsg1(20, "maxlines=%s\n", optarg);
         maxlines = (unsigned long) atol(optarg);
         break;

      case '?':
      default:
         usage();

      }
   }
   argc -= optind;
   argv += optind;

   if (argc < 1) {
      Pmsg0(0, _("Fatal error: no recipient given.\n"));
      usage();
      exit(1);
   }

   /*
    *  Determine SMTP server
    */
   if (mailhost == NULL) {
      if ((cp = getenv("SMTPSERVER")) != NULL) {
         mailhost = cp;
      } else {
         mailhost = "localhost";
      }
   }

#if defined(HAVE_WIN32)
   WSADATA  wsaData;

   _setmode(0, _O_BINARY);
   WSAStartup(MAKEWORD(2,2), &wsaData);
#endif

   /*
    *  Find out my own host name for HELO;
    *  if possible, get the FQDN - fully qualified domain name
    */
   if (gethostname(my_hostname, sizeof(my_hostname) - 1) < 0) {
      Pmsg1(0, _("Fatal gethostname error: ERR=%s\n"), strerror(errno));
      exit(1);
   }
#ifdef HAVE_GETADDRINFO
   memset(&hints, 0, sizeof(struct addrinfo));
   hints.ai_family = AF_UNSPEC;
   hints.ai_socktype = 0;
   hints.ai_protocol = 0;
   hints.ai_flags = AI_CANONNAME;

   if ((res = getaddrinfo(my_hostname, NULL, &hints, &ai)) != 0) {
      Pmsg2(0, _("Fatal getaddrinfo for myself failed \"%s\": ERR=%s\n"),
            my_hostname, gai_strerror(res));
      exit(1);
   }
   bstrncpy(my_hostname, ai->ai_canonname, sizeof(my_hostname));
   freeaddrinfo(ai);
#else
   if ((hp = gethostbyname(my_hostname)) == NULL) {
      Pmsg2(0, _("Fatal gethostbyname for myself failed \"%s\": ERR=%s\n"),
            my_hostname, strerror(errno));
      exit(1);
   }
   bstrncpy(my_hostname, hp->h_name, sizeof(my_hostname));
#endif
   Dmsg1(20, "My hostname is: %s\n", my_hostname);

   /*
    *  Determine from address.
    */
   if (from_addr == NULL) {
#if defined(HAVE_WIN32)
      DWORD dwSize = UNLEN + 1;
      LPSTR lpszBuffer = (LPSTR)alloca(dwSize);

      if (GetUserName(lpszBuffer, &dwSize)) {
         snprintf(buf, sizeof(buf), "%s@%s", lpszBuffer, my_hostname);
      } else {
         snprintf(buf, sizeof(buf), "unknown-user@%s", my_hostname);
      }
#else
      if ((pwd = getpwuid(getuid())) == 0) {
         snprintf(buf, sizeof(buf), "userid-%d@%s", (int)getuid(), my_hostname);
      } else {
         snprintf(buf, sizeof(buf), "%s@%s", pwd->pw_name, my_hostname);
      }
#endif
      from_addr = bstrdup(buf);
   }
   Dmsg1(20, "From addr=%s\n", from_addr);

   /*
    *  Connect to smtp daemon on mailhost.
    */
lookup_host:
#ifdef HAVE_GETADDRINFO
   memset(&hints, 0, sizeof(struct addrinfo));
   switch (default_resolv_type) {
   case RESOLV_PROTO_ANY:
      hints.ai_family = AF_UNSPEC;
      break;
   case RESOLV_PROTO_IPV4:
      hints.ai_family = AF_INET;
      break;
#ifdef HAVE_IPV6
   case RESOLV_PROTO_IPV6:
      hints.ai_family = AF_INET6;
      break;
#endif
   default:
      hints.ai_family = AF_UNSPEC;
      break;
   }
   hints.ai_socktype = SOCK_STREAM;
   hints.ai_protocol = 0;
   hints.ai_flags = 0;
   snprintf(mail_port, sizeof(mail_port), "%d", mailport);

   if ((res = getaddrinfo(mailhost, mail_port, &hints, &ai)) != 0) {
      Pmsg2(0, _("Error unknown mail host \"%s\": ERR=%s\n"),
            mailhost, gai_strerror(res));
      if (strcasecmp(mailhost, "localhost")) {
         Pmsg0(0, _("Retrying connection using \"localhost\".\n"));
         mailhost = "localhost";
         goto lookup_host;
      }
      exit(1);
   }

   for (rp = ai; rp != NULL; rp = rp->ai_next) {
#if defined(HAVE_WIN32)
      s = WSASocket(rp->ai_family, rp->ai_socktype, rp->ai_protocol, NULL, 0, 0);
#else
      s = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
#endif
      if (s < 0) {
         continue;
      }

      if (connect(s, rp->ai_addr, rp->ai_addrlen) != -1) {
         break;
      }

      close(s);
   }

   if (!rp) {
      Pmsg1(0, _("Failed to connect to mailhost %s\n"), mailhost);
      exit(1);
   }

   freeaddrinfo(ai);
#else
   if ((hp = gethostbyname(mailhost)) == NULL) {
      Pmsg2(0, _("Error unknown mail host \"%s\": ERR=%s\n"), mailhost,
         strerror(errno));
      if (strcasecmp(mailhost, "localhost") != 0) {
         Pmsg0(0, _("Retrying connection using \"localhost\".\n"));
         mailhost = "localhost";
         goto lookup_host;
      }
      exit(1);
   }

   if (hp->h_addrtype != AF_INET) {
      Pmsg1(0, _("Fatal error: Unknown address family for smtp host: %d\n"), hp->h_addrtype);
      exit(1);
   }
   memset((char *)&sin, 0, sizeof(sin));
   memcpy((char *)&sin.sin_addr, hp->h_addr, hp->h_length);
   sin.sin_family = hp->h_addrtype;
   sin.sin_port = htons(mailport);
#if defined(HAVE_WIN32)
   if ((s = WSASocket(AF_INET, SOCK_STREAM, 0, NULL, 0, 0)) < 0) {
      Pmsg1(0, _("Fatal socket error: ERR=%s\n"), strerror(errno));
      exit(1);
   }
#else
   if ((s = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
      Pmsg1(0, _("Fatal socket error: ERR=%s\n"), strerror(errno));
      exit(1);
   }
#endif
   if (connect(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
      Pmsg2(0, _("Fatal connect error to %s: ERR=%s\n"), mailhost, strerror(errno));
      exit(1);
   }
   Dmsg0(20, "Connected\n");
#endif

#if defined(HAVE_WIN32)
   int fdSocket = _open_osfhandle(s, _O_RDWR | _O_BINARY);
   if (fdSocket == -1) {
      Pmsg1(0, _("Fatal _open_osfhandle error: ERR=%s\n"), strerror(errno));
      exit(1);
   }

   int fdSocket2 = dup(fdSocket);

   if ((sfp = fdopen(fdSocket, "wb")) == NULL) {
      Pmsg1(0, _("Fatal fdopen error: ERR=%s\n"), strerror(errno));
      exit(1);
   }
   if ((rfp = fdopen(fdSocket2, "rb")) == NULL) {
      Pmsg1(0, _("Fatal fdopen error: ERR=%s\n"), strerror(errno));
      exit(1);
   }
#else
   if ((r = dup(s)) < 0) {
      Pmsg1(0, _("Fatal dup error: ERR=%s\n"), strerror(errno));
      exit(1);
   }
   if ((sfp = fdopen(s, "w")) == 0) {
      Pmsg1(0, _("Fatal fdopen error: ERR=%s\n"), strerror(errno));
      exit(1);
   }
   if ((rfp = fdopen(r, "r")) == 0) {
      Pmsg1(0, _("Fatal fdopen error: ERR=%s\n"), strerror(errno));
      exit(1);
   }
#endif

   /*
    * Send SMTP headers.  Note, if any of the strings have a <
    *  in them already, we do not enclose the string in < >, otherwise
    *  we do.
    */
   get_response(); /* banner */
   chat("HELO %s\r\n", my_hostname);
   chat("MAIL FROM:%s\r\n", cleanup_addr(from_addr, buf, sizeof(buf)));

   for (i = 0; i < argc; i++) {
      char *m = argv[i];
      if (m) {
         /* email1,email2,email3 */
         for (char *end = strchr(m, ','); end ; end = strchr(m, ',')) {
            *end = 0;
            Dmsg1(20, "rcpt to: %s\n", argv[i]);
            chat("RCPT TO:%s\r\n", cleanup_addr(m, buf, sizeof(buf)));
            m = end+1;            // Move forward
            *end = ',';           // Get the original string back
         }
         if (*m) {              // We should have a last one
            Dmsg1(20, "rcpt to: %s\n", argv[i]);
            chat("RCPT TO:%s\r\n", cleanup_addr(m, buf, sizeof(buf)));
         }
      }
   }

   if (cc_addr) {
      chat("RCPT TO:%s\r\n", cleanup_addr(cc_addr, buf, sizeof(buf)));
   }
   Dmsg0(20, "Data\n");
   chat("DATA\r\n");

   /*
    * Send header
    */
   fprintf(sfp, "From: %s\r\n", from_addr);
   Dmsg1(10, "From: %s\r\n", from_addr);
   if (subject) {
      fprintf(sfp, "Subject: %s\r\n", subject);
      Dmsg1(10, "Subject: %s\r\n", subject);
   }
   if (reply_addr) {
      fprintf(sfp, "Reply-To: %s\r\n", reply_addr);
      Dmsg1(10, "Reply-To: %s\r\n", reply_addr);
   }
   if (err_addr) {
      fprintf(sfp, "Errors-To: %s\r\n", err_addr);
      Dmsg1(10, "Errors-To: %s\r\n", err_addr);
   }

   if (sender_addr) {
      fprintf(sfp, "Sender: %s\r\n", sender_addr);
      Dmsg1(10, "Sender: %s\r\n", sender_addr);
   } else {

#if defined(HAVE_WIN32)
      DWORD dwSize = UNLEN + 1;
      LPSTR lpszBuffer = (LPSTR)alloca(dwSize);

      if (GetUserName(lpszBuffer, &dwSize)) {
         fprintf(sfp, "Sender: %s@%s\r\n", lpszBuffer, my_hostname);
         Dmsg2(10, "Sender: %s@%s\r\n", lpszBuffer, my_hostname);
      } else {
         fprintf(sfp, "Sender: unknown-user@%s\r\n", my_hostname);
         Dmsg1(10, "Sender: unknown-user@%s\r\n", my_hostname);
      }
#else
      if ((pwd = getpwuid(getuid())) == 0) {
         fprintf(sfp, "Sender: userid-%d@%s\r\n", (int)getuid(), my_hostname);
         Dmsg2(10, "Sender: userid-%d@%s\r\n", (int)getuid(), my_hostname);
      } else {
         fprintf(sfp, "Sender: %s@%s\r\n", pwd->pw_name, my_hostname);
         Dmsg2(10, "Sender: %s@%s\r\n", pwd->pw_name, my_hostname);
      }
#endif
   }
   /* Add custom header, if any */
   for (i=0; i<custom_header_count; i++) {
      fprintf(sfp, "%s\n", custom_headers[i]);
   }

   fprintf(sfp, "To: %s", argv[0]);
   Dmsg1(10, "To: %s", argv[0]);
   for (i = 1; i < argc; i++) {
      fprintf(sfp, ",%s", argv[i]);
      Dmsg1(10, ",%s", argv[i]);
   }

   fprintf(sfp, "\r\n");
   Dmsg0(10, "\r\n");
   if (cc_addr) {
      fprintf(sfp, "Cc: %s\r\n", cc_addr);
      Dmsg1(10, "Cc: %s\r\n", cc_addr);
   }

   if (content_utf8) {
      fprintf(sfp, "Content-Type: text/plain; charset=UTF-8\r\n");
      Dmsg0(10, "Content-Type: text/plain; charset=UTF-8\r\n");
   }

   get_date_string(buf, sizeof(buf));
   fprintf(sfp, "Date: %s\r\n", buf);
   Dmsg1(10, "Date: %s\r\n", buf);

   fprintf(sfp, "\r\n");

   /*
    * Send message body
    */
   lines = 0;
   while (fgets(buf, sizeof(buf), stdin)) {
      if (maxlines > 0 && ++lines > maxlines) {
         Dmsg1(20, "skip line because of maxlines limit: %lu\n", maxlines);
         while (fgets(buf, sizeof(buf), stdin)) {
            ++lines;
         }
         break;
      }
      buf[sizeof(buf)-1] = '\0';
      buf[strlen(buf)-1] = '\0';
      if (buf[0] == '.') {         /* add extra . see RFC 2821 4.5.2 */
         fputs(".", sfp);
      }
      fputs(buf, sfp);
      fputs("\r\n", sfp);
   }

   if (lines > maxlines) {
      Dmsg1(10, "hit maxlines limit: %lu\n", maxlines);
      fprintf(sfp, "\r\n\r\n[maximum of %lu lines exceeded, skipped %lu lines of output]\r\n", maxlines, lines-maxlines);
   }

   /*
    *  Send SMTP quit command
    */
   chat(".\r\n");
   chat("QUIT\r\n");
   exit(0);
}
